1. Field of Technology
The present invention relates to an image forming apparatus.
2. Description of Related Art
In image forming apparatuses such as a copying machine, a printer and a facsimile machine which employ an electrophotographic process, there are carried out image formations each being conducted through the process wherein an electrostatic latent image is formed on a photoconductor, and then, the electrostatic latent image is visualized with toner in a developer to be a toner image which is transferred onto a transfer member and is fixed.
The image forming apparatuses mentioned above are required to form images with higher image quality, and various methods to satisfy the requirement have been suggested. As one of these methods, for example, Japanese Patent No. 3728990 discloses a method to enhance stiffness of a skeletal portion of an image forming apparatus. Namely, it is one to enhance stiffness of the skeletal portion to eliminate a distortion of the whole of the image forming apparatus, and to arrange various units preserved in the skeletal portion so that their relative positional relations may be accurate.
Further, when a unit is replaced periodically, or when a unit needs to be replaced because of occurrence of troubles, there is sometimes an occasion where it is necessary to detect whether an installation position for the replaced new unit is the same as that in the initial state or not, in terms of positional accuracy.
When detecting the installation position of this kind, it is considered to utilize a fixed member that serves as a standard, and to measure a distance from the aforesaid member to the unit to be measured, as a detecting method. However, when assembly of an image forming apparatus in a prior art is completed, the member serving as a standard is covered by various types of units to be installed in the skeletal portion of the main body, in many cases, and large-scale disassembly is needed when utilizing the member representing the standard. Under certain circumstances, there is a possibility of occurrence of a problem that a unit is damaged in the middle of disassembly.